charles bender



@atten tntrs ut-rnt @Hita lurnovnn suspension-BRIDGE.

@te flgemle nient tu in tlgrse sticts "ggutcnt mit T0 ALL WHOM IT MAYCQNOERN: b

Be it known that I, CHARLES BENDER, of New York, in the county and Stateof New York, have invented.- a new and useful Improvement inSuspension-Bridges; and I do hereby declare that ,the following is afull` and exact description of the same, reference being had to theaccompanying drawings, audto the letters of` reference marked thereon.'

Y My invention refers particularly to the dilferentspccies of stitfenedsuspension-bridges, and its 'nature consists, first, in dividing orseparating the beams or trusses at one or more points, and connectingthem by yielding joints; further, in the attachment of the chains orcables to the beams or trusses of the bridge itself, instead offastening the same to abutments'; further, in the manner of securing theends of the bridge to the end piers vertically, and in such a manner asto allow for the expansion and contraction of the bridge; and, lastly,inattaching the beams or trusses to the central piers sidewise, andfastening them, at the same time, at one pier in such a manner as toprevent any horiz'ontal movement in the direction ofthe longitudinalaxis.of the bridge.

Figure I represents a longitudinal elevation of my improved bridge. b yb The remaining figures represent details, showing the .separate partson an enlarged scale, and will be more particularly referred to in thedescription. y

In thcaccompanying drawings, A represents the end or 'shore pier, and BB the central piers. C ai-e longitudinal trusses, constructed in theusual manner, subject to many variations, to correspond with thc styleand nature of the bridge. D, in Fig. I, represents. the yielding joints,at the point where the beams or trusses are separated. One of the manypossible plans of strengthening and stifening this part of thebeamscrtrusses, and ofjoining the same together by means of a strong bolt, E,is represented in Figure II.` l l The object of providing one or morejoints in the whole length of the beams or'trusses is topreventetlicreby any danger from the unequal expansion resulting fromthe different materials used in the construction of said beams ortrusses, as well as of the cables or chains, further to facilitatethereby the bendingiof thebrdge by changes of temperature, to equalizeany irregularity at the points of support of the structure'on the piers,and likewise to facilitate and rectify thereby considerably theanalytical calculation of the whole structure. The manner ofconstructing this joint, as well as the manner of strengthening theadjoining ends of the beams or trusses, is subject to many variations,and has to correspond with the style and nature of the bridge. In Fig. Ithis joint is represented exactly in the centre, between `the centralpiers B and B', but the same may be placed in different positions, andmay even be arranged at two or more4 places,'according to the nature`and to the number ofthe spans of the bridge, and may be used for alldescriptions of stitl'en'ed suspension-bridges. l

Between the shore pier A and the first central pier B, strongdiagonaltrusses F F, shown atan enlarged scale in Figure III, sheet 2,are arranged in the truss-work of the beams, having at their pointofjunction, near the middle of the height ofthe longitudinal beams ortrusses, astrong bolt, G, around which the cables or chains II arefastened. These trusses F transfer equally the horizont-al forces ofthecables or chains to the chords of the trusses, while strong uprights,J, resist theivertical pressure acting in the systemof the trusses F.

It is not essential by what arrangement of details `the strains ofthecables or chains are transferred tothe chords of the trusses or to thebeams. The only taski to be fulfilled is the equal distribution of saidstrains, and 'the annihilation ofthe different secondary forces; andthis may be effected by various arrangements ofthe different partsin asuitable manner. y i A The exact position of 'thc attachment of thc`chains or cables to the beams `or trusses depends likewise oncireumstanceaand may be either nea-rer to or farther away from the shorepier A and, in some cases, it may even be advisablelto extend the beamsor trusses beyond the said shore pierA, andplacc the point of attachmentof the chains or cables beyond said shore pier. Mathematical andanalytical examina-tion in cachsngle ease will determine the mostproiitable-positionof these points. i

By this arrangement of attaching the cables or chains to the beams crtrusses, a great saving is in most eases obtained, as I dispense therebywith a great part of the expensive masonry at present necessary, at eachend ofthe bridge, to secure the ends of the cables or chains. y l

'lhc cables or chains II are carried on the top ofthe central piers Baudl, and tllcbeam's or trusses 'C are suspended from the same in theusual manner. Below the ends of the bridge, rollers K arelplaced,provided with side flanges x a', itting over the surfaces of the platesn andante prevent Lanyside motion me thhgivgcmw tbc ends. The plate n issecurely fastened tothe under sident` thebeams orV trusses, and theplate m is attached to the top of the shore pier A. The ends of 'thebridge areat the same time fastened down by heavy bolts S, arranged oneach side of the roller K. The lower ends of these bolts-S are securelyfastened in the foundation of the piers, and are provided with suitablejoints, v to allow for the-horizontal motion of the beams or trusses,resulting from expansion or contraction, in consequence oftliccbange of.temperature.

This vertical anchorage of the ends of the beams or trusses of stitcnedsuspensiombridges to the endor shore piers, or near the ends et' thebridge, prevents any upward movement ot the trusscnds, in case of anyoverloadingr in certain contingencies.

This arrangement of fastening down the ends of the bridge is representedat an enlarged scale in Figure IV, in front view and cross-section. 4

To prevent the undulatory motion causedv by the wind, as well as forother rcasonsfhereafter mentioned,ll attach the outer beams or the cordsof the trusses et' the bridge to the central piers opposite the middleofthe same. Projections L are securely attached te the outside-ot thebeams orltrusses C, at the desired position, which enter into suitableguideframes N, fastened to the piers (s'eelFigureV) in such a manneraste brace thereby the bridge against the piQrSLsHVci-ent'play beingnlloW'cd'f-inoncor more of the same to allow "for the expansion orcontraction ofthe beams lengthwise. In the framesN'i'astened to thepiers, suitable plates w are arranged, against which theprojoctionsL,attached to the beams C, are made to bear, said plates wbeing capable of being regulated, by means of set-scrows a a. On thatpier which is either in the middlc'of-the bridge, or on that next to itscentre, I attach these be'amsin such a'manner as not to allow for ,anylong'ltu ldinal motion, whereby the differences of the length of tbcbridge, causedrby changes of temperature, are regu* '-lated, and broughtto a certainty, on either sid'e of this point oi" attncliment. By thisattachment of the beams or trusses, sidewise to the piers, `theprcssurecaused by the wiudis'partly annihilated, the side motion of thesame caused by the n'ind is considerably reduced, and the piersthemselves are strengthened, the pressure resulting from thosev causes,and which in otherY cases is all4 on the top'ot` said piers, where thecables or chains are supported, is brought thereby lower doivn, 'ornearer. to its`lase.

What I claim as my invention, and'dcsire to secure by Letters Patent, isf 1. The construction and arrangement of one or more yielding` joints,connecting the beams or trusses of stiilencd suspension-bridges,substantially as herein described.

-2. I claim the attachment of ther-.ends of the cables or chains, at ornear the iirst or shore piers, to the longitudinal beams or trussestofstiencd suspension-bridges, substantially as set forth;

3. I claim the means and method by which the ends of the beams ortrusses of stiifened. suspensionbridg'es are secured to the shore piersby vertical anchorage, and the arrangement of suitable 4joints v in saidanchors,

substantiallyfor the purpose described. i

1l. I claim the means and method employcdto rcducc the side mot-ion, byattaching the longitudinal beams or trusses of stiencdsuspension-bridges to the centrehlcrs sidewisc, said attachment being onone pier per.

fectly immovable in. any horinontal direction, while at the otl1`e`r'piers/allowance is made for the variations of the length ofthe beams,substantially as set forth and described. y

n Y i CHARLES BENDER. Witnesses s HENRY E. Rennen, WILLIAM Dnnrnn.,

